I love motorcycles. Always have, and I probably always will. I was very excited to see that Blizzard is introducing them in Wrath of the Lich King. I'll probably spec engineering on most of my characters just to make my own little biker gang. Wouldn't it be great to see a guild rolling around looking like Fel's Angels? But how would others know you are a guild?
Stonewhisper of Scarlet Crusade suggested some additional accessories from other crafters. I like his idea of having guild jackets for raiding. He also suggested using engineering for performance modifications. Something like a rocket fuel for a nitrous-oxide-like speed boost.* I could see a world of after-market parts for WoW bikes: blacksmiths could sell sissy seats and wheelie bars. Tailors could make saddle bags to add to carrying capacity. Taurens and Draenei would probably need some kind of suspension upgrade.
The original poster also suggested modifications to the license plate on the cycle mounts. The license plate in the model reads PWN. It could be interesting, but difficult to create personalized plates in-game. I would probably get POSER on mine, since that is my current bike plate or maybe PWNSTAR, which will be mine if I ever get a Bronco. What would your plate say?
* In the real world this doesn't work out so well with a cruiser type bike. I once saw a guy running Nos on a Harley on the drag strip. I was a wee bit upset when he blew out his O-rings and it took the track crew the better part of an hour to get the oil off the track. There are many parts of the game that wouldn't work out so well IRL.